Catalytic dehydrogenation of propanol-2 on Na-Zr phosphates containing Cu, Co, and Ni

The dehydrogenation of propanol-2 on sodium-zirconium phosphates (NZP) with the composition Na 1 - 2xM xZr 2(PO 4) 3 (x = 0.125 and 0.25) in which Na + ions were replaced by M 2+ = Co 2+, Ni 2+, and Cu 2+ ions was studied. The experimental reaction activation energy E a decreased while transition through the T* = 310-340°C temperature; above this temperature, the electrophysical and crystallographic properties of the material changed. These changes were explained by the reversible transfer of Me 2+ ions from position M1 to M2 in the NZP lattice. Me 2+ centers with different alcohol adsorption forms at T < T* (one-point) and T > T* (two-point) participated in the dehydrogenation reaction. For the first form, E a and the logarithm of the preexponential factor linearly correlated with the ionic radius of M 2+. The activity of M-NZP catalysts altered in repeated experiments and in cases when the direction of temperature variations changed. © Pleiades Publishing, Ltd., 2012.